1. Field of the Invention
The embodiments of the invention generally relate to integrated circuit manufacturing, and more particularly to techniques for identifying defects in integrated circuits during manufacturing.
2. Description of the Related Art
Damascene processing typically involves the deposition of liner films between metal and insulating layers. These liner films should generally be completely removed in non-damascene areas in a subsequent chemical mechanical polishing (CMP) process. However, the CMP process typically does not adequately remove all of the liner material due to the local topography from circuit pattern factors and defects, which are both compounded by the general non-uniformity of the CMP process.
Usually, the residual liner films in between the metal layers in an integrated circuit device cannot be detected during standard inspections thereby causing metal shorting of various structures in the device, which cause significant major yield loss and reliability failure of the device. Undoubtedly, it would be quite advantageous if the residual liner films were easily detectable during a subsequent inspection process. However, typical residual films appear transparent when viewed by optical inspection. Thus, they generally cannot be detected by routine optical inspection. Therefore, there remains a need for a novel technique that allows for easier and more precise inspections of damascene structures.